In WordPress, PHP calls with MYSQ call L which is faster

In WordPress, PHP calls and MYSQ calls L which is faster
Wordpress
You want to invoke the corresponding picture according to the category ID
PHP words, want to write a case Judgment statement to invoke
or write a MySQL value, and then write a statement called
Some sort of a researcher.
Could you tell me which one is faster?
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Maintainability is naturally MySQL dominant
The query speed depends on your file organization

If you write 500 case, then you should be dismissed.
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Only the MySQL value is written, is it not the same to be taken out to judge?

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